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when the following equation is balanced, what is the coefficient for O2? C5H12+O2 CO2 + H2O

A. 8
B. 12
C. 14
D. 16

3 answers

To balance the equation \( \text{C}5\text{H}{12} + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O} \), we start by balancing the number of carbon (C), hydrogen (H), and oxygen (O) atoms on both sides.

  1. Carbon (C): There are 5 carbon atoms in \( \text{C}5\text{H}{12} \), so we need 5 \( \text{CO}_2 \): \[ \text{C}5\text{H}{12} + \text{O}_2 \rightarrow 5 \text{CO}_2 + \text{H}_2\text{O} \]

  2. Hydrogen (H): There are 12 hydrogen atoms in \( \text{C}5\text{H}{12} \), so we need 6 \( \text{H}_2\text{O} \) to balance the hydrogen: \[ \text{C}5\text{H}{12} + \text{O}_2 \rightarrow 5 \text{CO}_2 + 6 \text{H}_2\text{O} \]

  3. Counting Oxygens: Now we count the oxygens on the products side:

    • From \( 5 \text{CO}_2 \): \( 5 \times 2 = 10 \) O
    • From \( 6 \text{H}_2\text{O} \): \( 6 \times 1 = 6 \) O
    • Total Oxygens = \( 10 + 6 = 16 \)

  4. Balancing Oxygens: On the reactants side, \( \text{O}_2 \) contributes 2 O atoms per molecule. To get 16 O atoms, we divide by 2: \[ \frac{16}{2} = 8 \] So, we need 8 \( \text{O}_2 \).

The balanced equation is: \[ \text{C}5\text{H}{12} + 8 \text{O}_2 \rightarrow 5 \text{CO}_2 + 6 \text{H}_2\text{O} \]

Thus, the coefficient for \( \text{O}_2 \) is 8.

Final Answer: A. 8

if the reactants on the left side of a chemical equation are C2H5OH + 3O2 the products in a balanced equation could be
A. 2CO2 + 4H2O
B. 2CO2 + 3H2O
C. 3CO2 + 2H2O
D. 4CO2 + 3H2O

To determine the correct balanced products of the reaction given the reactants \( \text{C}_2\text{H}_5\text{OH} + 3\text{O}_2 \), we first need to understand what products are likely when ethanol (\( \text{C}_2\text{H}_5\text{OH} \)) combusts.

When ethanol combusts completely in oxygen, the products are typically carbon dioxide (\( \text{CO}_2 \)) and water (\( \text{H}_2\text{O} \)). The general combustion reaction can be represented as follows:

\[ \text{C}_x\text{H}_y + O_2 \rightarrow CO_2 + H_2O \]

Step 1: Write the unbalanced equation

Starting from the given reactants: \[ \text{C}_2\text{H}_5\text{OH} + 3\text{O}_2 \rightarrow ??? \]

Step 2: Determine the number of carbon and hydrogen atoms

In \( \text{C}_2\text{H}_5\text{OH} \):

  • There are 2 carbon (C) atoms.
  • There are 6 hydrogen (H) atoms.

Step 3: Writing the products

From the ethanol, we will produce:

  • 2 \( \text{CO}_2 \) (for the 2 carbon atoms)
  • To balance the hydrogen, since there are 6 hydrogens, we will produce 3 \( \text{H}_2\text{O} \) (since each water molecule contains 2 hydrogen atoms).

Step 4: Formulate the balanced equation

Putting this together, the balanced equation will be: \[ \text{C}_2\text{H}_5\text{OH} + 3\text{O}_2 \rightarrow 2\text{CO}_2 + 3\text{H}_2\text{O} \]

Step 5: Verify the options

Now let's look at the options given:

  • A. \( 2\text{CO}_2 + 4\text{H}_2\text{O} \) (Incorrect, too many H)
  • B. \( 2\text{CO}_2 + 3\text{H}_2\text{O} \) (Correct)
  • C. \( 3\text{CO}_2 + 2\text{H}_2\text{O} \) (Incorrect, too many Cs)
  • D. \( 4\text{CO}_2 + 3\text{H}_2\text{O} \) (Incorrect, too many Cs)

Thus, the balanced products for the reaction are:

Final Answer: B. \( 2\text{CO}_2 + 3\text{H}_2\text{O} \)